Various subterranean formations contain hydrocarbons in fluid form which can be produced to a surface location for collection. However, many of these formations also contain fluids, e.g. water, including brine, and gases, which can intrude on the production of hydrocarbon fluids. Accordingly, it often is necessary to control the intrusion of water through various techniques, including mechanical separation of the water from the hydrocarbon fluids and controlling the migration of water to limit the intrusion of water into the produced hydrocarbon fluids. However, these techniques tend to be relatively expensive and complex.
In a typical production example, a wellbore is drilled into or through a hydrocarbon containing formation. The wellbore is then lined with a casing, and a completion, such as a gravel pack completion, is moved downhole. The completion contains a screen through which hydrocarbon fluids flow from the formation to the interior of the completion for production to the surface. The annulus between the screen and the surrounding casing or wellbore wall often is gravel packed to control the buildup of sand around the screen. During production, a phenomenon known as watercut sometimes occurs in which water migrates along the wellbore towards the screen into which the hydrocarbon fluids flow for production. If the watercut becomes too high, water can mix with the produced hydrocarbon fluids. Unless this migration of water is controlled, the well can undergo a substantial reduction in efficiency or even be rendered no longer viable.